Highly dispersed noble metal isomerization dewaxing catalyst, its preparation method and application

Abstract

The application provides a high-dispersion noble metal isomerization dewaxing catalyst and a preparation method and application thereof, wherein the preparation method comprises the following steps: dissolving a noble metal precursor in a mixed solution of water, alcohol and a ligand, and uniformly mixing to obtain a noble metal precursor solution; wherein the mass ratio of water to alcohol is 20-1:1, and the molar ratio of the ligand to noble metal atoms is 6-18:1; the carrier particles are immersed in the noble metal precursor solution, and are subjected to ultrasonic oscillation, drying and calcination in an air atmosphere to obtain the high-dispersion noble metal isomerization dewaxing catalyst; wherein, based on the total weight of the carrier particles being 100%, the amount of noble metal is 0.1-0.6% in terms of atomic mass. The high-dispersion noble metal isomerization dewaxing catalyst provided by the application has high noble metal dispersion, and thus has high isomerization dewaxing catalytic activity.

Description

TECHNICAL FIELD

[0001] The present application relates to a highly dispersed noble metal isomerization dewaxing catalyst, its preparation method and application, and belongs to the technical field of molecular sieve catalysts. BACKGROUND

[0002] Lubricating oil base oil is one of the important products of oil refining and refinery profit, with the market demand for high quality and long life of lubricating oil increasingly strict, the demand for II, III type base oil produced by isomerization dewaxing technology increases year by year. The noble metal dispersion technology of isomerization dewaxing catalyst is mainly used in isomerization dewaxing, make-up refining and white oil hydrogenation catalyst preparation in lubricating oil hydrogenation isomerization technology, and the isomerization dewaxing technology of lubricating oil is the most advanced lubricating oil base oil production technology at present. The key technology of isomerization dewaxing is the preparation of noble metal catalyst, for the high isomerization selectivity and low cracking activity of bifunctional catalyst, the active metal generally uses Pt and Pd noble metal, which plays a dehydrogenation and hydrogenation role on alkane or olefin, the dispersion degree of noble metal determines the number of effective metal sites, noble metal loading and noble metal hydrogenation performance, and further determines the catalyst performance and production cost; the carrier is mainly molecular sieve, which provides acidity and plays a pore restriction and shape selection role in the isomerization reaction process, the molecular sieve generally uses one-dimensional straight channel structure of aluminum phosphate and silicon aluminum molecular sieve, typical representatives are SAPO-11, ZSM-22, ZSM-23, ZSM-48 and ZSM-12, etc., the pore confinement effect and acidity characteristics determine the difference of molecular conversion capacity and product structure for different raw materials.

[0003] Some prior art related to the present application and the defects or disadvantages of the prior art relative to the present application will be briefly introduced as follows:

[0004] CN 113694962 A discloses an isomerization dewaxing catalyst for hydrocracking tail oil and a preparation method thereof, which first uses a ball mill to ball mill two different types of molecular sieves, then adds a group VIII B metal element oxide or metal salt for ball milling, and finally kneads, extrudes, dries and calcines to prepare the isomerization dewaxing catalyst. The defects of this technology or the disadvantages of the present application include: ball milling may cause the collapse of molecular sieve channels, and ball milling does not improve the metal dispersion.

[0005] CN 112915997 A discloses a preparation method of carbon-loaded high-dispersion noble metal catalyst, which places noble metal precursor in the quartz reaction tube of a tube furnace, heats to more than half of the noble metal melting point temperature, i.e. 600-1200℃, so that the noble metal reaches a surface melting state, introduces carbon-containing gas, the space-time velocity of the carbon-containing gas is 6-600 liters per gram of noble metal per hour, and the reaction lasts for 1-24 hours, so that carbon and hydrogen are generated by pyrolysis of the carbon-containing gas, and the free diffusion of the surface-melted noble metal atoms migrates to the unsaturated sites of the newly generated carbon to form a stable carbon-loaded high-dispersion noble metal catalyst. The defects of this technology or the deficiencies of the present application include: the reaction temperature is relatively high, and it is relatively dangerous to introduce methane and other carbon-containing gases at high temperature.

[0006] CN 113101969 A discloses a molecular sieve loaded single-atom catalyst and a preparation method thereof, which is to mix and react molecular sieve and water-soluble metal salt solution in a reaction kettle, the solvent of the metal salt solution is selected from at least one of water, methanol, ethanol, propanol, isopropanol and butanol, the mixing reaction temperature is 60-150℃, the reaction time is 2-10 days, the unreacted metal salt is removed by filtration or centrifugation to obtain a solid filter cake, and then the solid filter cake is calcined at 500-650℃ for 2-12 hours. The defects of this technology or the deficiencies of the present application include: the metal solution directly reacts with the molecular sieve, and the metal ions or alcohol molecular sieves are easy to enter the molecular sieve channel, causing the molecular sieve channel to be blocked.

[0007] CN 111135840 A discloses a preparation method of a supported single-atom dispersed noble metal catalyst, which dissolves noble metal precursor in deionized water or common organic solvents, and then adds an appropriate amount of common inorganic and organic reagents containing N, P and S to obtain a noble metal precursor complex solution (the mass concentration of noble metal is 0.0001-5%); a certain amount of carrier is immersed in the noble metal precursor complex solution, stirred for 1-600 minutes, filtered, and dried at 60-120℃ for 6-12 hours to obtain a noble metal catalyst precursor; a certain amount of the above catalyst precursor is placed in He, Ar, N2, H2, O2, air and other atmospheres and treated at 200-800℃ for 10-600 seconds to obtain a supported single-atom dispersed noble metal catalyst. The defects of this technology or the deficiencies of the present application include: the common inorganic and organic reagents containing N, P and S are not fully combusted in He, Ar, N2 and H2 atmospheres, and the residues of N, P and S elements are easy to poison and deactivate the catalyst.

[0008] CN 109126774 A discloses a kind of ultra-high dispersion supported monatomic noble metal catalyst and its preparation method, which dissolves metal precursor in water or ethanol, the obtained solution is impregnated on the carrier, water bath 60-80 ℃, solvent is evaporated dry, 100-120 ℃ in oven drying 8-24 h, 250-400 ℃ calcination under N2 protection 4-12 h, or H2 atmosphere 250-400 ℃ reduction 4-12 h.CO and pumped halogenated alkane are preheated and vaporized, mixed into the tubular reactor containing calcined or reduced granular or powdered catalyst, the temperature of CO and halogenated alkane mixed gas treatment is 50-280 ℃, the pressure is 0.1-2.0 MPa, the volume space velocity is 100-5000 h -1 , time is 0.1-10 h, the molar ratio of CO and halogenated alkane is 0.1-4, the catalyst is first raised to the treatment temperature under N2 atmosphere protection, then switched to CO and halogenated alkane mixed gas treatment, after treatment, it is lowered to room temperature under N2 protection, to obtain supported monatomic noble metal catalyst.The catalyst is composed of two parts of metal and carrier, the metal is Ru, Rh, Pd, Ag, Ir, Pt, Au; the metal accounts for 0.01-10.0wt% of the total mass of the catalyst, and the carrier is activated carbon, graphene, silicon oxide, alumina.The defects of the technology or the deficiencies of the present application include: the use of atmosphere process in the preparation process of the catalyst is complex, CO and halogenated alkane gas has certain danger at high temperature, and industrial production has certain difficulty.

[0009] Therefore, there are many problems in the preparation process of high dispersion noble metal catalyst at present: the introduction of P, N, S and other elements in the preparation process of noble metal precursor solution may reduce the catalyst activity if not removed completely; the noble metal precursor is prepared in a molten state at a high temperature; a complex atmosphere is used to prevent noble metal aggregation during catalyst calcination, which is relatively dangerous; ball milling, impregnation and other operations have limited effect on improving noble metal dispersion, etc.Therefore, it is the research focus to prepare suitable noble metal precursor solution, reduce the introduction of impurity elements, use suitable impregnation dispersion process to make noble metal precursor fully dispersed on the surface of the catalyst, and adopt a simple and easy-to-operate calcination process to prevent noble metal aggregation during calcination, etc., to improve noble metal dispersion and catalyst noble metal utilization rate.

[0010] In summary, it has become a technical problem urgently needed to be solved in the art to provide a new high dispersion noble metal isomerization dewaxing catalyst, its preparation method and application. SUMMARY

[0011] In order to solve the above-mentioned shortcomings and deficiencies, one object of the present application is to provide a preparation method of high dispersion noble metal isomerization dewaxing catalyst.

[0012] Another object of the present application is to provide a high-dispersed noble metal isodewaxing catalyst prepared by the above-mentioned method for preparing a high-dispersed noble metal isodewaxing catalyst.

[0013] Another object of the present application is to provide an application of the above-mentioned high-dispersed noble metal isodewaxing catalyst in catalyzing isodewaxing reaction to prepare lubricating oil base oil.

[0014] Another object of the present application is to provide a method for preparing lubricating oil base oil by isodewaxing, wherein the catalyst used is the above-mentioned high-dispersed noble metal isodewaxing catalyst.

[0015] To achieve the above-mentioned objects, in one aspect, the present application provides a method for preparing a high-dispersed noble metal isodewaxing catalyst, wherein the method comprises:

[0016] Step one: dissolving noble metal precursor in a mixture of water, alcohol and ligand to obtain a noble metal precursor solution; wherein the mass ratio of water to alcohol is 20-1:1, preferably 20-5:1, more preferably 10:1, and the molar ratio of ligand to noble metal atom is 6-18:1, preferably 12:1;

[0017] Step two: immersing carrier particles in the noble metal precursor solution, and then performing ultrasonic oscillation, drying and calcination in air atmosphere to obtain the high-dispersed noble metal isodewaxing catalyst; wherein, based on the total weight of the carrier particles being 100%, the amount of noble metal is 0.1-0.6% by atomic mass, preferably 0.2-0.4%.

[0018] As a specific embodiment of the above-mentioned preparation method of the present application, the noble metal precursor is a noble metal salt, and the noble metal salt includes one or a combination of several of chloroplatinic acid, tetraammine platinum nitrate, platinum nitrate, palladium nitrate, palladium chloride, nickel chloride, nickel nitrate, etc., preferably chloroplatinic acid.

[0019] As a specific embodiment of the above-mentioned preparation method of the present application, the alcohol includes one or a combination of several of ethanol, propanol, isopropanol, glycerol, etc., preferably ethanol.

[0020] As a specific embodiment of the above-mentioned preparation method of the present application, the ligand includes a ligand containing one carboxyl group or one carbonyl group.

[0021] As a specific embodiment of the above-mentioned preparation method of the present application, the relative molecular weight of the ligand is 90-200.

[0022] As a specific embodiment of the above preparation method of the present application, the ligand comprises one or a combination of sorbic acid, salicylic acid, nicotinamide, lactic acid, etc., and preferably sorbic acid.

[0023] As a specific embodiment of the above preparation method of the present application, the mixing is performed at 30-60°C for 2-6h.

[0024] As a specific embodiment of the above preparation method of the present application, the ultrasonic oscillation is performed at 30-60°C for 2-6h, and preferably at 50°C for 4h.

[0025] As a specific embodiment of the above preparation method of the present application, the carrier particles are obtained by mixing the molecular sieve, alumina, acid solution, binder and deionized water uniformly and then kneading and extruding into strips;

[0026] The mass ratio of the molecular sieve, alumina, acid solution, binder and deionized water (excluding the deionized water in the acid solution) is 1:0.2-0.6:0.3-0.6:0.01-0.1:0.3-1, and preferably 1:0.3-0.5:0.4-0.5:0.05-0.1:0.5-0.8.

[0027] As a specific embodiment of the above preparation method of the present application, the molecular sieve comprises one or a combination of SAPO-11, SAPO-31, ZSM-12, ZSM-22, ZSM-23, ZSM-48, etc., and preferably ZSM-48.

[0028] As a specific embodiment of the above preparation method of the present application, the acid solution comprises a nitric acid or phosphoric acid solution with a mass concentration of 5-10wt%, and preferably 5-10wt% nitric acid.

[0029] As a specific embodiment of the above preparation method of the present application, the binder comprises one or a combination of amaranth powder, titanium dioxide, methyl cellulose, etc.

[0030] As a specific embodiment of the above preparation method of the present application, when the binder comprises amaranth powder and titanium dioxide or methyl cellulose and titanium dioxide, the mass ratio of the amaranth powder or methyl cellulose to the titanium dioxide is 10-30:1,

[0031] Preferably, the binder comprises amaranth powder and titanium dioxide, and the mass ratio of the amaranth powder to the titanium dioxide is 20:1.

[0032] As a specific embodiment of the above-mentioned preparation method of the present application, the alumina is common alumina such as pseudo-boehmite.

[0033] The size of the carrier particles is not specifically required in the present application, and can be reasonably selected according to the actual needs of the site operation, as long as the purpose of the present application can be achieved.

[0034] As a specific embodiment of the above-mentioned preparation method of the present application, the temperature of the drying is 100-120℃, preferably 120℃, and the time is 2-4h, preferably 2h.

[0035] As a specific embodiment of the above-mentioned preparation method of the present application, the temperature of the calcination is 450-600℃, preferably 500-550℃, more preferably 550℃, and the time is 4-6h, preferably 6h.

[0036] In another aspect, the present application also provides a high-dispersion noble metal isomerization dewaxing catalyst, wherein the high-dispersion noble metal isomerization dewaxing catalyst is prepared by the above-mentioned preparation method of the high-dispersion noble metal isomerization dewaxing catalyst, wherein the noble metal is fully dispersed on the surface and internal pores of the carrier particles, and the content of the noble metal is 0.1-0.6% by mass based on 100% of the total weight of the carrier particles. The internal pores of the carrier particles are the pores formed by the accumulation of molecular sieves.

[0037] In yet another aspect, the present application also provides the use of the above-mentioned high-dispersion noble metal isomerization dewaxing catalyst in the preparation of lubricating oil base oil by catalyzing isomerization dewaxing reaction.

[0038] In still another aspect, the present application also provides a method for preparing lubricating oil base oil by isomerization dewaxing, wherein the catalyst used in the method is the above-mentioned high-dispersion noble metal isomerization dewaxing catalyst.

[0039] Compared with the prior art, the present application can achieve the following beneficial technical effects:

[0040] (1) the present application, when preparing the noble metal precursor solution, dissolves the noble metal precursor in the mixed solution of water, alcohol and ligand with certain molecular size, and the noble metal and the ligand form complex reaction in the alcohol solvent to form noble metal ligand with larger molecular size, so that the distance between noble metal atoms is increased, and the resistance in the aggregation process is increased, thereby preventing the noble metal from aggregating in the high-temperature calcination process, and improving the dispersion of the noble metal; in addition, the ligand used in the present application, such as sorbic acid, salicylic acid and lactic acid, only contains one carboxyl group, while nicotinamide only contains one carbonyl group, compared with citric acid containing three carboxyl groups and oxalic acid containing two carboxyl groups, the ligand used in the present application has smaller pH adjustment ability and weaker acidity, has smaller influence on the molecular sieve skeleton structure, and more ligands are required when the ligand with one carboxyl group or one carbonyl group is complexed with noble metal atoms, which is beneficial to hinder the formation of metal bond between noble metal atoms, thereby being beneficial to metal dispersion;

[0041] (2) the present application, after the carrier particles are immersed in the noble metal precursor solution, ultrasonic oscillation is carried out, that is, ultrasonic oscillation is carried out during the immersion process, so that the noble metal ligand formed above is uniformly dispersed on the surface of the carrier particles, the noble metal aggregation is prevented during the drying and calcination process, and the dispersion of the noble metal is improved;

[0042] (3) the present application avoids or reduces the addition of elements such as P, N and S when preparing the noble metal precursor solution, which can reduce the difficulty of subsequent treatment of the catalyst, thereby improving the activity of the catalyst. BRIEF DESCRIPTION OF DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiment description will be briefly introduced below, and obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0044] Figure 1 STEM image of the noble metal isomerization dewaxing catalyst provided in embodiment 2 of the present application.

[0045] Figure 2 STEM image of the noble metal isomerization dewaxing catalyst provided in embodiment 3 of the present application.

[0046] Figure 3 STEM image of the noble metal isomerization dewaxing catalyst provided in embodiment 4 of the present application.

[0047] Figure 4 STEM image of the noble metal isomerization dewaxing catalyst provided in comparative example 1.

[0048] Figure 5STEM image of the noble metal isomerization dewaxing catalyst provided for Comparative Example 2.

[0049] Figure 6 STEM image of the noble metal isomerization dewaxing catalyst provided for Comparative Example 3.

[0050] Figure 7 STEM image of the noble metal isomerization dewaxing catalyst provided for Comparative Example 4. DETAILED DESCRIPTION

[0051] It has to be understood that the term "comprising", or variations such as "comprise" or "comprises", as used in the present specification and in the claims, is not intended to exclude that at least one of the stated steps or elements can be present in the process, method, system, product or apparatus. It is further understood that the terms "including", "containing", "comprising" and "having" are used interchangeably in the present specification and in the claims.

[0052] The ranges disclosed herein are given using the format "from about 'lower limit' to about 'upper limit'." The ranges can be from one or more of the lower limits to one or more of the upper limits. The selected lower limit and upper limit define the range. The lower limit and upper limit define the boundaries of the particular range. All ranges disclosed herein are combinable, i.e., any lower limit can be combined with any upper limit to form a range. For example, if a range is disclosed as 60-120 and 80-110, it is understood that 60-110 and 80-120 are also disclosed. Furthermore, if a range is disclosed as 1-3, 2-4, and 5, it is understood that 1-5, 2-3, 2-4, and 3-5 are also disclosed.

[0053] In the present application, unless otherwise stated, the numerical range "a-b" represents a shorthand for the inclusion of any and all combinations of real numbers between a and b, wherein a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" have been listed in the present application, and "0-5" is just a shorthand for these combinations of numbers.

[0054] In the present application, unless otherwise stated, all embodiments and preferred embodiments mentioned in the present application can be combined with each other to form new technical solutions.

[0055] In the present application, unless otherwise stated, all technical features and preferred features mentioned in the present application can be combined with each other to form new technical solutions.

[0056] In the present application, unless otherwise stated, the term "two" used in the present specification means "at least two".

[0057] In the present application, if not otherwise specified, all the steps mentioned herein can be carried out in sequence or randomly, but preferably in sequence. For example, the method comprises steps (a) and (b), which means that the method can comprise steps (a) and (b) in sequence, or steps (b) and (a) in sequence. For example, the method mentioned herein can further comprise step (c), which means that step (c) can be added to the method in any order, for example, the method can comprise steps (a), (b) and (c), or steps (a), (c) and (b), or steps (c), (a) and (b), etc.

[0058] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in combination with the accompanying tables, drawings and examples. The examples described below are part of the examples of the present application, but not all the examples, and are only used to illustrate the present application, and should not be regarded as limiting the scope of the present application. Based on the examples in the present application, all the other examples obtained by those skilled in the art without making creative efforts fall within the scope of protection of the present application. If the specific conditions are not specified in the examples, the conventional conditions or the conditions recommended by the manufacturer are used. If the reagents or instruments used are not specified by the manufacturer, they are all conventional products that can be purchased on the market.

[0059] Example 1

[0060] The present example provides a noble metal isomerization dewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0061] Step one: weigh 100g ZSM-48 molecular sieve, 20g pseudo-boehmite, 9.23g 65wt% nitric acid and 50.77g deionized water, 4.55g sesbania powder, 0.45g titanium dioxide, 49.23g deionized water, mix uniformly, knead and extrude into particles to form carrier particles;

[0062] The mass ratio of each component in the carrier is: molecular sieve: alumina: acid solution: binder: deionized water = 1:0.2:0.6:0.05:0.4923;

[0063] The mass ratio of sesbania powder to titanium dioxide is 10.11:1;

[0064] Step two: dissolve 0.21g chloroplatinic acid in a mixed solution of 57.14g deionized water, 2.86g ethanol and 1.03g sorbic acid, mix at 50°C for 2 hours to prepare a noble metal precursor solution;

[0065] In the noble metal precursor solution:

[0066] water: alcohol = 20: 1 by mass;

[0067] ligand: noble metal = 18: 1 by atom mole ratio;

[0068] noble metal: carrier particle = 0.1% by mass;

[0069] Step three: immerse the carrier particles in the noble metal precursor solution, ultrasonic oscillation at 30°C for 2 hours, drying at 120°C for 2 hours, calcination at 500°C for 4 hours in an air atmosphere, to obtain the noble metal isomerization dewaxing catalyst.

[0070] Example 2

[0071] The present embodiment provides a noble metal isomerization dewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0072] Step one: weigh 100g ZSM-48 molecular sieve, 50g alumina, 7.69g 65wt% nitric acid, 42.31g deionized water, 4.76g sesbania powder, 0.24g titanium dioxide, 37.69g deionized water, mix uniformly, knead and extrude into carrier particles;

[0073] The mass ratio of each component in the carrier is: molecular sieve: alumina: acid solution: binder: deionized water = 1:0.5:0.5:0.05:0.3769;

[0074] Sesbania powder: titanium dioxide = 19.83: 1 by mass;

[0075] Step two: dissolve 0.63g tetraammine platinum nitrate in a mixed solution of 54.56g deionized water, 5.45g propyl alcohol, and 2.19g sorbic acid, mix at 30°C for 6 hours, to prepare a noble metal precursor solution;

[0076] In the noble metal precursor solution:

[0077] water: alcohol = 10: 1 by mass;

[0078] ligand: noble metal = 12: 1 by atom mole ratio;

[0079] noble metal: carrier = 0.3% by mass;

[0080] Step three: immerse the carrier particles in the noble metal precursor solution, ultrasonic oscillation at 40°C for 4 hours, drying at 120°C for 2 hours, calcination at 500°C for 4 hours in an air atmosphere, to obtain the noble metal isomerization dewaxing catalyst.

[0081] Example 3

[0082] The embodiment provides a noble metal isomerization dewaxing catalyst which is prepared by a preparation method comprising the following specific steps.

[0083] Step one: 100g of ZSM-12 molecular sieve, 40g of alumina, 4.12g of 85wt% phosphoric acid, 45.88g of deionized water, 0.95g of methyl cellulose, 0.05g of titanium dioxide and 34.12g of deionized water are weighed and uniformly mixed, and then kneaded and extruded into a strip to form carrier particles;

[0084] The mass ratio of the components in the carrier is: molecular sieve: alumina: acid solution: binder: deionized water = 1:0.4:0.5:0.01:0.3412;

[0085] The mass ratio of methyl cellulose to titanium dioxide is 19:1;

[0086] Step two: 0.49g of platinum nitrate is dissolved in a mixed solution of 25g of deionized water, 25g of isopropyl alcohol and 1.28g of salicylic acid, and mixed at 60°C for 3 hours to prepare a noble metal precursor solution;

[0087] The noble metal precursor solution comprises:

[0088] The mass ratio of water to alcohol is 1:1;

[0089] The atomic molar ratio of the ligand to the noble metal is 6:1;

[0090] The mass ratio of the noble metal to the carrier is 0.3%;

[0091] Step three: the carrier particles are immersed in the noble metal precursor solution, ultrasonically oscillated at 60°C for 2 hours, dried at 120°C for 2 hours, and calcined at 550°C for 6 hours in an air atmosphere to obtain the noble metal isomerization dewaxing catalyst.

[0092] Embodiment 4

[0093] The embodiment provides a noble metal isomerization dewaxing catalyst which is prepared by a preparation method comprising the following specific steps.

[0094] Step one: 100g of ZSM-22 molecular sieve, 50g of alumina, 3.69g of 65wt% nitric acid, 36.31g of deionized water, 6.77g of sesbania powder, 0.23g of titanium dioxide and 33.69g of deionized water are weighed and uniformly mixed, and then kneaded and extruded into a strip to form carrier particles;

[0095] The mass ratio of the components in the carrier is: molecular sieve: alumina: acid solution: binder: deionized water = 1:0.5:0.4:0.07:0.3369;

[0096] Rice powder: titanium dioxide = 29.43:1 by mass ratio;

[0097] Step two: 0.65g of palladium nitrate is dissolved in a mixed solution of 90.9g of deionized water, 9.1g of glycerol, and 4.15g of nicotinamide, and mixed at 40°C for 4 hours to prepare a noble metal precursor solution;

[0098] In the noble metal precursor solution:

[0099] Water: alcohol = 10:1 by mass ratio;

[0100] Ligand: noble metal = 12:1 by atomic mole ratio;

[0101] Noble metal: carrier = 0.5% by mass ratio;

[0102] Step three: the carrier particles are immersed in the noble metal precursor solution, ultrasonically oscillated at 40°C for 2 hours, dried at 120°C for 4 hours, and calcined at 600°C for 6 hours in an air atmosphere to obtain the noble metal isomerization dewaxing catalyst.

[0103] Example 5

[0104] The present embodiment provides a noble metal isomerization dewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0105] Step one: 100g of SAPO-11 molecular sieve, 60g of alumina, 1.76g of 85wt% phosphoric acid, 28.24g of deionized water, 9.1g of rice powder, 0.9g of titanium dioxide, and 30g of deionized water are weighed and uniformly mixed, and then extruded and formed into carrier particles by kneading;

[0106] The mass ratio of each component in the carrier is: molecular sieve: alumina: acid solution: binder: deionized water = 1:0.6:0.3:0.1:0.3;

[0107] Rice powder: titanium dioxide = 10.11:1 by mass ratio;

[0108] Step two: 1g of palladium chloride is dissolved in a solution of 66.67g of deionized water, 13.33g of ethanol, and 6.61g of lactic acid, and mixed at 60°C for 5 hours to prepare a noble metal precursor solution;

[0109] In the noble metal precursor solution:

[0110] Water: alcohol = 5:1 by mass ratio;

[0111] Ligand: noble metal = 13:1 by atomic mole ratio;

[0112] Noble metal: carrier = 0.6% by mass ratio;

[0113] Step three: immerse the carrier particles in the noble metal precursor solution, ultrasonic oscillation at 50°C for 2 hours, drying at 120°C for 2 hours, calcination at 500°C for 5 hours in air atmosphere, to obtain the noble metal isomerization dewaxing catalyst.

[0114] Example 6

[0115] The present example provides a noble metal isomerization dewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0116] Step one: weigh 100g of SAPO-11 molecular sieve, 60g of alumina, 1.76g of 85wt% phosphoric acid, 28.24g of deionized water, 9.1g of sesbania powder, 0.9g of titanium dioxide, and 30g of deionized water, mix uniformly, knead and extrude into particles, to form carrier particles;

[0117] The mass ratio of each component in the carrier is: molecular sieve: alumina: acid solution: binder: deionized water = 1:0.6:0.3:0.1:0.3;

[0118] The mass ratio of sesbania powder to titanium dioxide is 10.11:1;

[0119] Step two: dissolve 0.89g of nickel chloride in 64g of deionized water, 16g of propyl alcohol, and 9.5g of salicylic acid solution, mix at 50°C for 6 hours, to prepare a noble metal precursor solution;

[0120] In the noble metal precursor solution:

[0121] The mass ratio of water to alcohol is 4:1;

[0122] The atomic molar ratio of ligand to noble metal is 10:1;

[0123] The mass ratio of noble metal to carrier is 0.4%;

[0124] Step three: immerse the carrier particles in the noble metal precursor solution, ultrasonic oscillation at 50°C for 2 hours, drying at 120°C for 2 hours, calcination at 500°C for 5 hours in air atmosphere, to obtain the noble metal isomerization dewaxing catalyst.

[0125] Example 7

[0126] The present example provides a noble metal isomerization dewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0127] Step one: take 100g SAPO-11 molecular sieve, 60g alumina, 1.76g 85wt% phosphoric acid, 28.24g deionized water, 9.1g sesbania powder, 0.9g titanium dioxide, 30g deionized water, mix uniformly, knead and extrude into strips to form carrier particles;

[0128] The mass ratio of each component in the carrier is: molecular sieve: alumina: acid solution: binder: deionized water = 1:0.6:0.3:0.1:0.3;

[0129] The mass ratio of sesbania powder to titanium dioxide is 10.11:1;

[0130] Step two: dissolve 0.94g nickel nitrate hexahydrate in 66.67g deionized water, 13.33g glycerol, 5.1g lactic acid solution, mix at 40°C for 4 hours, prepare a noble metal precursor solution;

[0131] In the noble metal precursor solution:

[0132] The mass ratio of water to alcohol is 5:1;

[0133] The atomic molar ratio of ligand to noble metal is 11:1;

[0134] The mass ratio of noble metal to carrier is 0.3%;

[0135] Step three: immerse the carrier particles in the noble metal precursor solution, ultrasonic oscillation at 50°C for 2 hours, drying at 120°C for 2 hours, calcination in air atmosphere at 500°C for 5 hours, to obtain the noble metal isomerization dewaxing catalyst.

[0136] Comparative Example 1

[0137] This comparative example provides a noble metal isomerization dewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0138] Step one: take 100g ZSM-48 molecular sieve, 20g pseudo-boehmite, 9.23g 65wt% nitric acid, 50.77g deionized water, 4.55g sesbania powder, 0.45g titanium dioxide, 49.23g deionized water, mix uniformly, knead and extrude into strips to form carrier particles;

[0139] The mass ratio of each component in the carrier is: molecular sieve: alumina: acid solution: binder: deionized water = 1:0.2:0.6:0.05:1;

[0140] The mass ratio of sesbania powder to titanium dioxide is 10.11:1;

[0141] Step two: 0.21 g chloroplatinic acid was dissolved in a mixed solution of 57.14 g deionized water and 2.86 g ethanol, and mixed at 50°C for 2 hours to prepare a noble metal precursor solution;

[0142] In the noble metal precursor solution:

[0143] The mass ratio of water to alcohol was 20:1;

[0144] The mass ratio of noble metal to carrier was 0.1%;

[0145] Step three: the carrier particles were immersed in the noble metal precursor solution, ultrasonically oscillated at 30°C for 2 hours, dried at 120°C for 2 hours, and calcined at 500°C for 4 hours in an air atmosphere to obtain a noble metal isomerization dewaxing catalyst.

[0146] Comparative Example 2

[0147] This comparative example provides a noble metal isomerization dewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0148] Step one: 100 g ZSM-48 molecular sieve, 50 g alumina, 7.69 g 65 wt% nitric acid, 42.31 g deionized water, 4.76 g sesbania powder, 0.24 g titanium dioxide, and 37.69 g deionized water were mixed uniformly, kneaded and extruded into carrier particles;

[0149] The mass ratio of each component in the carrier was: molecular sieve: alumina: acid solution: binder: deionized water = 1:0.5:0.5:0.05:0.8;

[0150] The mass ratio of sesbania powder to titanium dioxide was 19.83:1;

[0151] Step two: 0.63 g chloroplatinic acid was dissolved in 60 g deionized water, and mixed at 50°C for 2 hours to prepare a noble metal precursor solution;

[0152] Step three: the carrier particles were immersed in the noble metal precursor solution, the mass ratio of noble metal to carrier was 0.3%, ultrasonically oscillated at 40°C for 4 hours, dried at 120°C for 2 hours, and calcined at 500°C for 4 hours in an air atmosphere to obtain a noble metal isomerization dewaxing catalyst.

[0153] Comparative Example 3

[0154] This comparative example provides a noble metal isomerization dewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0155] Step one: take 100g ZSM-48 molecular sieve, 20g pseudo-boehmite, 9.23g 65wt% nitric acid and 50.77g deionized water, 4.55g sesbania powder, 0.45g titanium dioxide, 49.23g deionized water, mix uniformly, knead and extrude into strips to form carrier particles;

[0156] The mass ratio of each component in the carrier is: molecular sieve: alumina: acid solution: binder: deionized water = 1:0.2:0.6:0.05:1;

[0157] The mass ratio of sesbania powder to titanium dioxide is 10.11:1;

[0158] Step two: dissolve 0.21g chloroplatinic acid (409.818) in a mixed solution of 57.14g deionized water, 2.86g ethanol, and 1.77g citric acid (192.12), mix at 50°C for 2 hours, to prepare a noble metal precursor solution;

[0159] In the noble metal precursor solution:

[0160] The mass ratio of water to alcohol is 20:1;

[0161] The atomic molar ratio of ligand to noble metal is 18:1;

[0162] The mass ratio of noble metal to carrier particles is 0.1%;

[0163] Step three: immerse the carrier particles in the noble metal precursor solution, ultrasonic oscillation at 30°C for 2 hours, drying at 120°C for 2 hours, calcination in air atmosphere at 500°C for 4 hours, to obtain the noble metal isomerization dewaxing catalyst.

[0164] Comparative Example 4

[0165] This comparative example provides a noble metal isomerization dewaxing catalyst, which is prepared by a preparation method comprising the following specific steps:

[0166] Step one: take 100g ZSM-22 molecular sieve, 50g alumina, 3.69g 65wt% nitric acid and 36.31g deionized water, 6.77g sesbania powder, 0.23g titanium dioxide, 13.69g deionized water, mix uniformly, knead and extrude into strips to form carrier particles;

[0167] The mass ratio of each component in the carrier is: molecular sieve: alumina: acid solution: binder: deionized water = 1:0.5:0.4:0.07:0.5;

[0168] The mass ratio of sesbania powder to titanium dioxide is 29.43:1;

[0169] Step two: 0.21 g chloroplatinic acid (409.818) was dissolved in a mixed solution of 57.14 g deionized water, 2.86 g ethanol, and 0.83 g oxalic acid (90.03) to prepare a noble metal precursor solution, and the mixture was stirred at 50°C for 2 hours;

[0170] In the noble metal precursor solution:

[0171] The mass ratio of water to alcohol was 20:1.

[0172] The atomic molar ratio of ligand to noble metal was 18:1.

[0173] The mass ratio of noble metal to carrier particles was 0.1%.

[0174] Step three: the carrier particles were immersed in the noble metal precursor solution, ultrasonically shaken at 30°C for 2 hours, dried at 120°C for 2 hours, and calcined at 500°C for 4 hours in an air atmosphere to obtain the noble metal isomerization dewaxing catalyst.

[0175] Characterization test example 1

[0176] STEM tests were performed on the noble metal isomerization dewaxing catalysts provided by example 2 to example 4 and comparative example 1 to comparative example 4 in this characterization test example, and the STEM images obtained are shown in FIGS. 1 to 5, respectively. Figures 1-7 Figures 1-3 The small bright spots in FIGS. 1 to 5 are noble metal (platinum or palladium) particles, indicating that the noble metal particles in the noble metal isomerization dewaxing catalysts provided by example 2 to example 4 are small and well dispersed. Figures 1-3 It can be reasonably expected that the noble metal particles in the noble metal isomerization dewaxing catalysts provided by example 1 and example 5 are also small and well dispersed. Figures 4-7 In FIGS. 6 to 10, the bright spots are also noble metal particles, and the bright spots are large, indicating that the noble metal particles in the noble metal isomerization dewaxing catalysts provided by comparative example 1 to comparative example 4 have large clusters and poor dispersion, thereby indicating that the noble metal isomerization dewaxing catalysts cannot be prepared when no ligand is used or other ligands such as ligands containing multiple hydroxyl groups are used.

[0177] Catalyst performance evaluation example

[0178] In this evaluation example, the noble metal isomerization dewaxing catalyst provided by example 1 was subjected to a micro-reaction performance evaluation under the reaction conditions of a hydrogenated cracking tail oil as a raw material, a reaction temperature of 340°C and 360°C, a reaction pressure of 15 MPa, a hydrogen to oil ratio of 600:1, and a volume space velocity of 1.5 h -1

[0179] The parameters of the hydrogenated cracking tail oil raw material are shown in Table 1.​​

[0180] Table 1

[0181]

[0182] The evaluation results obtained in the evaluation example are shown in Table 2 below.

[0183] Table 2

[0184]

[0185]

[0186] As can be seen from Table 2 above, compared with the noble metal isomerization dewaxing catalysts provided by Comparative Examples 1 and 4, the noble metal isomerization dewaxing catalysts provided by the present application Examples 1 and 4 have smaller noble metal particles and better dispersion, and the hydrogenation activity is significantly improved, so that under the same reaction temperature conditions, the full-range condensation point can be reduced, the total base oil yield can be increased, the heavy base oil yield can be increased, and the viscosity index, pour point, and cloud point of the heavy base oil can be significantly improved.

[0187] The above description is merely specific embodiments of the present application, and cannot limit the scope of the application. Therefore, the replacement of equivalent components or the equivalent changes and modifications made within the scope of the present application should still fall within the scope of the present patent. In addition, the technical features in the present application can be freely combined with each other, and the technical features can be freely combined with each other.

Claims

1. A method for preparing a highly dispersed noble metal isomerization dewaxing catalyst, characterized in that, The preparation method includes: Step 1: Dissolve the noble metal precursor in a mixture of water, alcohol and ligand, and mix thoroughly to obtain a noble metal precursor solution; wherein, the mass ratio of water to alcohol is 20-1:1, the molar ratio of ligand to noble metal atoms is 6-18:1, and the ligand includes ligands containing one carboxyl group or one carbonyl group; Step 2: The carrier particles are immersed in a noble metal precursor solution, and then subjected to ultrasonic vibration, drying and calcination in an air atmosphere to obtain the highly dispersed noble metal isomer dewaxing catalyst; wherein, based on the total weight of the carrier particles as 100%, the amount of noble metal used is 0.1-0.6% by atomic mass.

2. The preparation method according to claim 1, characterized in that, The noble metal precursor is a noble metal salt, which includes one or a combination of several of the following: chloroplatinic acid, tetraammineplatinum nitrate, platinum nitrate, palladium nitrate, and palladium chloride.

3. The preparation method according to claim 1 or 2, characterized in that, The alcohols include one or a combination of several of ethanol, propanol, isopropanol, and glycerol.

4. The preparation method according to claim 1, characterized in that, The ligands include one or a combination of several of sorbic acid, salicylic acid, nicotinamide, and lactic acid.

5. The preparation method according to claim 1 or 2, characterized in that, The mixing process is carried out at 30-60℃ for 2-6 hours to achieve uniform mixing.

6. The preparation method according to claim 1 or 2, characterized in that, The ultrasonic oscillation is performed at 30-60℃ for 2-6 hours.

7. The preparation method according to claim 1 or 2, characterized in that, The carrier particles are obtained by mixing molecular sieves, alumina, acid solution, binder and deionized water evenly and then kneading and extruding them into strips. The mass ratio of molecular sieve, alumina, acid solution, binder and deionized water is 1:0.2-0.6:0.3-0.6:0.01-0.1:0.3-1.

8. The preparation method according to claim 7, characterized in that, The molecular sieve includes one or a combination of several of SAPO-11, SAPO-31, ZSM-12, ZSM-22, ZSM-23, and ZSM-48.

9. The preparation method according to claim 7, characterized in that, The acid solution includes a nitric acid or phosphoric acid solution with a mass concentration of 5-10 wt%.

10. The preparation method according to claim 7, characterized in that, The adhesive comprises one or a combination of several of the following: guar gum powder, titanium dioxide, and methylcellulose.

11. The preparation method according to claim 10, characterized in that, When the adhesive comprises guar gum powder and titanium dioxide or methylcellulose and titanium dioxide, the mass ratio of guar gum powder or methylcellulose to titanium dioxide is 10-30:

1.

12. The preparation method according to claim 1 or 2, characterized in that, The roasting temperature is 450-600℃ and the time is 4-6 hours.

13. A highly dispersed noble metal isomerization dewaxing catalyst, characterized in that, The highly dispersed noble metal isomer dewaxing catalyst is prepared by the preparation method of the highly dispersed noble metal isomer dewaxing catalyst according to any one of claims 1-12, wherein the noble metal is fully dispersed on the surface and internal pores of the support particles, and the noble metal content is 0.1-0.6% based on the total weight of the support particles (100%) and atomic mass.

14. The application of the highly dispersed noble metal isomerization dewaxing catalyst according to claim 13 in the preparation of lubricating oil base oil by catalytic isomerization dewaxing reaction.

15. A method for preparing lubricating oil base oil through isomerization dewaxing, characterized in that, The catalyst used in the method is the highly dispersed noble metal isomer dewaxing catalyst as described in claim 13.

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